When Al Gore ran for president in 2000, he said, "Our Constitution is a living and breathing document" that changes its meaning over time. This week, we learned that among the things changing in Gore's Constitution is the war power. It meant one thing when Bill Clinton was president, but means another thing now.

Seven years ago, then-Vice President Gore supported Clinton in launching a war Congress didn't authorize. Now, he says the Constitution denies President Bush the power merely to intercept an enemy's communications in and out of the United States -- without permission from a federal judge -- in the midst of a war Congress did authorize.

The program in question has been described by Gen. Michael Hayden, principal deputy director for national intelligence, as yielding information about terrorists that could not have been gleaned through court-ordered wiretaps, while intercepting only international communications involving persons linked to Al-Qaida.

Yet on Monday, Gore described the program as "eavesdropping on huge numbers of American citizens" and claimed it "virtually compels the conclusion that the president of the United States has been breaking the law, repeatedly and insistently."

While the liberal ACLU and Center for Constitutional Rights are bringing lawsuits against the program, Gore is calling for a special counsel to investigate Bush.

Now flash back to 1999 -- the year when only a failed Senate impeachment prosecution stood between Gore and the presidency.

On March 23, 1999, President Clinton ordered U.S. forces to begin bombing Yugoslavia because of its treatment of people in Kosovo. Clinton bombed for three months. The day the war started, then-White House Spokesman Joe Lockhart was asked whether Clinton believed congressional support was "constitutionally necessary." Lockhart said, "Well, I don't think he believes it's constitutionally necessary because we don't believe that."

Congress, in fact, declined to authorize it. The Senate voted 58 to 41 for a resolution "authorizing the president of the United States to conduct military air operations and missile strikes against the Federal Republic of Yugoslavia." But the House defeated the resolution, 213 to 213.

Gore aggressively backed Clinton's unauthorized war, suggesting its critics were guilty of "politics." "I think the American people want to see politics removed from any kind of action where our military forces are involved overseas," he said on the April 2, 1999, edition of CNN's "Larry King Live."

Was the Clinton-Gore Kosovo War constitutional? No.

As I have argued before, citing Louis Fisher's "Presidential War Power," the Framers unambiguously denied the president the power to initiate offensive military action. But as Framers James Madison and Elbridge Gerry, authors of the war-powers clause, explained at the Constitutional Convention, they did leave "to the executive the power to repel sudden attacks."

In the Founding era, no one doubted Congress needed to approve any act of war beyond what was necessary for the president "to repel sudden attacks." In the 1801 case Talbot v. Seeman, involving a ship seized as a war prize, Chief Justice Marshall explained: "The whole powers of war being, by the Constitution of the United States, vested in Congress, the acts of that body can alone be resorted to as our guides in this inquiry. It is not denied, nor in the course of the argument has it been denied, that Congress may authorize general hostilities, in which case the general laws of war apply to our situation; or partial hostilities, in which case the laws of war, so far as they actually apply to our situation, must be noticed."

Was Clinton repelling a sudden attack on the United States when he bombed Yugoslavia? Even Gore never claimed that.

In the war against al-Qaida -- including his order for the NSA to intercept al-Qaida-linked communications in and out of the United States -- was President Bush acting either under a congressional war authorization or his own authority to repel sudden attacks?

He was doing both.

After 9-11, Congress authorized the president to make war against "those nations, organizations or persons he determines planned, authorized, committed or aided the terrorist attacks." If this authorized the president to invade Afghanistan, surely it authorized him to intercept communications between the United States and suspected terrorists in Afghanistan.

But even if Congress hadn't authorized a war, it is reasonable to conclude the president could intercept al-Qaida-linked communications in and out of the United States even in circumstances where a court-order could not be secured. Surely, the president's authority to repel sudden attacks includes the authority to listen at our frontier for sounds from the enemy.

But -- at least so long as there is a Republican in the White House -- it seems that Gore's "living and breathing" Constitution would put earplugs in the sentries who guard the border between us and the next 9-11.